Summary

This dataset provides tree inventory, tree height, diameter at breast height (DBH), and estimated crown measurements from 30 plots located in the Tapajos National Forest, Para, Brazil collected in September 2010. The plots were located in primary forest, primary forest subject to reduced-impact selective logging (PFL) between 1999 and 2003, and secondary forest (SF) with different age and disturbance histories. Plots were centered on GLAS (the Geoscience Laser Altimeter System) LiDAR instrument footprints selected along two sensor acquisition tracks spanning a wide range in vertical structure and aboveground biomass.

Eight of the 50 x 50-m plots were located in primary forests, eight were in primary forest subject to reduced-impact selective logging (PFL) between 1999 and 2003, and 14 plots were in secondary forest (SF) with different age and disturbance histories. All trees were identified as to their species or genus (when species was uncertain) level. Measurements were taken for each living tree 5-cm or greater in diameter in early successional stands and 10-cm or greater in all other stands. DBH was recorded to the nearest 0.1 cm, height to the base of the live crown and total height were estimated visually to the nearest 0.5-m, and crown depth was calculated as the difference between total height and base to the live crown. For a 12.5-m × 50-m subplot extending along the major axis of the GLAS footprint, crown radius was measured in two orthogonal directions by projecting the edge of the crown to the ground and recording its horizontal distance to the trunk to the nearest 0.1 m using a tape measure.

There is one data file in comma-separated format (.csv) with this dataset that contains the biometric and tree inventory data. There is also one file in shapefile (.shp) format with plot location information. This file is also provided as a companion file in .kmz format for viewing in Google Earth.

Figure 1. Geographical location of the Tapajos National Forest, PA, Brazil, outlined in yellow. The gray lines are GLAS tracks from 2003 to 2009 and the blue circles are the plots sampled. The pictures on the right illustrate three of the stands where plots were located (Goncalves et al., 2017).

Table of Contents

Data Set Overview

This dataset provides tree inventory, tree height, diameter at breast height (DBH), and estimated crown measurements from 30 plots located in the Tapajos National Forest, Para, Brazil collected in September 2010. The plots were located in primary forest, primary forest subject to reduced-impact selective logging (PFL) between 1999 and 2003, and secondary forest (SF) with different age and disturbance histories. Plots were centered on GLAS (the Geoscience Laser Altimeter System) LiDAR instrument footprints selected along two sensor acquisition tracks spanning a wide range in vertical structure and aboveground biomass.

Eight of the 50 x 50-m plots were located in primary forests, eight were in primary forest subject to reduced-impact selective logging (PFL) between 1999 and 2003, and 14 plots were in secondary forest (SF) with different age and disturbance histories. All trees were identified as to their species or genus (when species was uncertain) level. Measurements were taken for each living tree 5-cm or greater in diameter in early successional stands and 10-cm or greater in all other stands. DBH was recorded to the nearest 0.1 cm, height to the base of the live crown and total height were estimated visually to the nearest 0.5-m and calibrated with a laser rangefinder, as described by Gonçalves (2014), and crown depth was calculated as the difference between total height and base to the live crown. For a 12.5-m × 50-m subplot extending along the major axis of the GLAS footprint, crown radius was measured in two orthogonal directions by projecting the edge of the crown to the ground and recording its horizontal distance to the trunk to the nearest 0.1 m using a tape measure.

The Tapajos National Forest is located along highway BR-163, approximately 50 km south of the city of Santarem, Pará, in the central Brazilian Amazon.

Study Plots: Locations of the 30 study plots in the Tapajos National Forest, Para, Brazil. Coordinates are the centroid of the respective 50 x 50 m plot.

Plot

Longitude

Latitude

Elevation (m)

1

-54.953095

-3.130912

90.9

2

-54.952725

-3.133013

102.4

3

-54.952627

-3.133861

106.2

4

-54.967090

-3.027957

144.9

5

-54.966862

-3.029513

138.9

6

-54.967549

-3.024846

162.5

7

-54.968220

-3.020171

161.9

8

-54.979361

-2.937596

178.7

9

-54.979570

-2.936039

182.8

10

-54.979781

-2.934482

182

11

-54.979154

-2.939156

175.7

12

-54.967318

-3.026402

149.4

13

-54.968581

-3.017016

159.9

14

-54.952407

-3.135418

110

15

-54.968882

-3.015529

162.8

16

-54.950032

-3.152583

106.6

17

-54.950426

-3.149415

95.2

18

-54.955232

-3.115119

91.5

19

-54.955037

-3.116719

97.4

20

-54.955014

-3.118327

111.8

21

-54.983555

-3.112966

94.2

22

-54.983762

-3.114550

97.4

23

-54.983340

-3.111408

95.8

24

-54.985405

-3.125354

95.5

25

-54.985105

-3.123851

92.7

26

-54.984877

-3.122297

96

27

-54.949660

-2.865231

176.2

28

-54.949474

-2.863790

175.9

29

-54.949029

-2.860537

177.7

30

-54.949234

-2.862164

173.3

Data File Information

This dataset includes one data file in comma-separated (.csv) format and one shapefile (.shp). The shapefile data are also provided in .kmz format for viewing in Google Earth (forest_inventory_tapajos.kmz).

Table 1. Data files and descriptions

File name

Description

Tapajos_inventory_data_2010.csv

A file in comma-separated (.csv) format with the inventory and biometric measurements

forest_inventory_tapajos.zip

When unzipped, this file contains a shapefile (.shp) with the plot locations. The data are also provided in .kmz format for viewing in Google Earth

Table 2. Variables in the data fileTapajos_inventory_data_2010.csv. See Figure 2 for description of local x-y coordinate system.

Missing or data not provided are reported as -9999.

Column name

Units

Description

plot

Plot number

type

SF=secondary; SLF=selectively logged; PF=primary

origin

Plot corner which serves as the origin for the local cartesian system. NE or SW. See Figure 2.

tree

Tree identification number

family

Scientific family to which the tree belongs

genus

Genus to which the tree belongs

scientific_name

Full scientific name for the tree Genus species

common_name

Local common name

density_wood

g cm-3

Wood density (literature values)

dbh

cm

Diameter at breast height measured at 1.3 meters above the ground

ht_crown_base

m

Height to the base of crown

ht_total

m

Total tree height

depth_crown

m

Crown depth

stem_x

m

Tree stem location along the x coordinate

stem_y

m

Tree stem location along the y coordinate

crown_radius_x0

m

Crown radius measured from the crown edge closest to the plot origin to the stem along the x coordinate

crown_radius_x50

m

Crown radius measured from the stem to the edge furthest away from the plot origin along the x coordinate

crown_radius_y0

m

Crown radius measured from the crown edge closest to the plot origin to the stem along the y coordinate

crown_radius_y50

m

Crown radius measured from the stem to the edge furthest away from the plot origin along the y coordinate

ht_crown_max_x0

m

Height to the maximum crown width at the edge of the crown closest to the plot origin along the x coordinate

ht_crown_max_x50

m

Height to the maximum crown width at the edge of the crown farthest from the plot origin along the x coordinate

ht_crown_max_y0

m

Height to the maximum crown width at the edge of the crown closest to the plot origin along the y coordinate

ht_crown_max_y50

m

Height to the maximum crown width at the edge of the crown farthest from the plot origin along the y coordinate

shape_coeff_crown_x0

unitless

Shape coefficient for the crown above the maximum crown radius estimated at the crown edge closest to the plot origin along the x coordinate

shape_coeff_crown_x50

unitless

Shape coefficient for the crown above the maximum crown radius estimated at the crown edge furthest from the plot origin along the x coordinate

shape_coeff_crown_y0

unitless

Shape coefficient for the crown above the maximum crown radius estimated at the crown edge closest to the plot origin along the y coordinate

shape_coeff_crown_y50

unitless

Shape coefficient for the crown above the maximum crown radius estimated at the crown edge furthest from the plot origin along the y coordinate

shape_coeff_crown_below_x0

unitless

Shape coefficient for the crown below the maximum crown radius estimated at the crown edge closest to the plot origin along the x coordinate

shape_coeff_crown_below_x50

unitless

Shape coefficient for the crown below the maximum crown radius estimated at the crown edge furthest from the plot origin along the x coordinate

shape_coeff_crown_below_y0

unitless

Shape coefficient for the crown below the maximum crown radius estimated at the crown edge closest to the plot origin along the y coordinate

shape_coeff_crown_below_y50

unitless

Shape coefficient for the crown below the maximum crown radius estimated at the crown edge furthest from the plot origin along the y coordinate

Shapefile properties

Table 3. Attributes in the shapefile forest_inventory_tapajos.shp

Attribute

Description

plot

Plot ID

elev_m

Elevation in meters

area_ha

Area in hectares

The shapefile is also provided as a companion file in .kmz format for viewing in Google Earth (forest_inventory_tapajos.kmz)

Application and Derivation

These data could be useful to climate change studies as well as forest management and deforestation-reforestation studies.

Quality Assessment

Uncertainties resulting from differences in repeated measurements of DBH, height to the base of the live crown, total height,08 crown depth, and crown radius were determined. DBH was the most precisely measured quantity, with a RMSD of less than 2%. Repeated measurements of height were typically within 1 m of each other (RMSD = 15%–18%), with approximately half of the height to the base of the live crown, and a quarter of the total height observations showing identical repeated measurements. Crown depth and crown radius measurements showed considerably less agreement (RMSD of 31 and 26%, respectively). However, with the exception of DBH, there was no evidence of a systematic difference between first and second measurements. For DBH, the data suggested that the second measurement produced values that were lower to a statistically significant degree when compared to the first measurement, although the estimated median difference of less than 0.1 cm has no practical significance. There is considerable discussion of uncertainties in Goncalves et al. (2017).

There was no evidence that absolute differences between repeated measurements (both the mean and the rate of change) varied with forest type, after accounting for differences in the magnitude of the measurements.

Table 4. Summary statistics of differences between repeated measurements of DBH, height to the base of the live crown, total height, crown depth, and crown radius for trees sampled at Tapajos. Statistics include total error (RMSD), systematic error (mean), and random error (SD), in both absolute and relative terms. The number of observations was 104, except for cr (n = 144) (Goncalves et al., 2017).

Attribute

Range

Differences

RMSD

Mean

SD

% That Is:

0

≤10%

≤25%

DBH

5.5-110.5

0.8 (1.8%)

0.1 (0.5%)

0.8 (1.8%)

23.1

100

100

Crown Depth

1-20.0

1.8 (30.7%)

-0.3 (-4.8%)

1.8 (30.5%)

32.7

33.7

71.2

Height to Base of Crown

1.5-31

1.8 (17.7%)

0.1 (0.5%)

1.8 (17.7%)

47.1

54.8

83.7

Total Height

5.0-40.0

2.3 (15.2%)

-0.2 (-1,7%)

2.3 (15.2%)

24

53.8

93.3

Crown Radius

0.7-8.0

0.8 (25.7%)

0

0.8 (25.8%)

11.8

37.5

68.8

Data Acquisition, Materials, and Methods

Study Site

The Tapajos National Forest is located along highway BR-163, approximately 50 km south of the city of Santarrem Para, in the central Brazilian Amazon. The climate is tropical monsoon, with a mean annual temperature of 25 degrees C and annual precipitation of 1,909 mm, with a 5-month dry season (<100 mm month) between July and November.

The vegetation is dense, upland, tropical moist forest. Common genera among 193 tree species sampled in this study include Psychotria (Rubiaceae), Protium (Burseraceae), Otoba (Myristicaceae), Eschweilera (Lecythidaceae), Pouteria (Sapotaceae), and Rinorea (Violaceae) in primary forests, and Cecropia (Urticaceae), Banara (Salicaceae), and Inga (Fabaceae) in secondary forests. The soils are nutrient-poor oxisols and ultisols, with low pH, organic matter, and cation exchange capacity, and a high concentration of aluminum oxides. Our sample sites were situated on a relatively flat plateau, with the elevation ranging from approximately 80 to 180 m (Goncalves et al., 2017).

Field Data

Field data were collected in September 2010 in 30 0.25-ha plots (50 x 50-m). Of the 30 plots, eight were primary forest (PF), eight were primary forest subject to reduced-impact selective logging (PFL) between 1999 and 2003, and 14 were secondary forest (SF) with different age and disturbance histories. Plots were centered on Geoscience Laser Altimeter System (GLAS) LiDAR instrument footprints selected along two sensor acquisition tracks, spanning a wide range in vertical structure and aboveground biomass. The GLAS instrument that was aboard the NASA Ice, Cloud, and land Elevation (ICESat) satellite. Individual plot centers were located on the ground using a total station and the Differential Global Positioning System (DGPS).

Field biometric measurements included diameter at breast height (DBH) measured with a diameter tape at 1.3 m and recorded to the nearest 0.1 cm; height to the base of the live crown (HC) and total height (HT), estimated visually by experienced members of the field crew to the nearest 0.5 m and crown depth (CD), calculated as the difference between HT and HC. Measurements were taken for each living tree 5-cm or greater in diameter in early successional stands and 10 cm or greater in all other stands.

For a 12.5-m x 50-m subplot extending along the major axis of the GLAS footprint, crown radius (CR) was measured in two orthogonal directions by projecting the edge of the crown to the ground and recording its horizontal distance to the trunk to the nearest 0.1 m using a tape measure (Goncalves et al., 2017). All trees were identified as to their species or genus (when species was uncertain) level and assigned a wood density value (r, oven-dry weight over green volume) derived from the literature (Chave et al., 2006; Reyes et al., 1992).